Single turbo upgrade - sizing options for a mild 2.6

[shodan]

Hi SAU, happy NY to you all.

I'm looking into a power upgrade for my 32gtr, educating myself on options. I've done a fair bit of reading on SAU and elsewhere, and now I'm hoping to get some advice about turbo selection from experienced folk here.

Currently running:

Mild 2.6L with forged pistons and rods, fresh mild ported head, oem cams, adj. cam gears, JUN oil pump, extended sump, oem cold side, N1 turbos. With supporting mods this is good for a modest 281kw at the wheels on 98.

Goal:

380-400kw at the wheels, with a nice wide torque band and response that is no worse than current, and preferably better. This is a regularly driven street car that will see the odd squirt here and there, cheeky track days etc.

Some considerations:

I think I'd rather go EWG and get the manifold + wg + bov stuff done, in preparation for an engine refresh inc stroker upgrade in future.

 

Some of the thoughts/suggestions so far:

EFR7670 ewg 1.05 - highly responsive but limited to around 350-360kw on 2.6Ls?

EFR8374 ewg 1.05 - good power but better suited to 2.8L?

GTX3576R GEN II 1.06

 

Thanks in advance!

Edited January 8, 2019 by shodan

[HarrisRacing]

Hi SAU, happy NY to you all.
I'm looking into a power upgrade for my 32gtr, educating myself on options. I've done a fair bit of reading on SAU and elsewhere, and now I'm hoping to get some advice about turbo selection from experienced folk here.
Currently running:
Mild 2.6L with forged pistons and rods, fresh mild ported head, oem cams, adj. cam gears, JUN oil pump, extended sump, oem cold side, N1 turbos. With supporting mods this is good for a modest 281kw at the wheels on 98.
Goal:
380-400kw at the wheels, with a nice wide torque band and response that is no worse than current, and preferably better. This is a regularly driven street car that will see the odd squirt here and there, cheeky track days etc.
Some considerations:
I think I'd rather go EWG and get the manifold + wg + bov stuff done, in preparation for an engine refresh inc stroker upgrade in future.
 
Some of the thoughts/suggestions so far:
EFR7670 ewg 1.05 - highly responsive but limited to around 350-360kw on 2.6Ls?
EFR8374 ewg 1.05 - good power but better suited to 2.8L?
GTX3576R GEN II
 
Thanks in advance!

Go with the 8374. You will NOT be disappointed

[Mick_o]

Not likely a 7670 would be limited to 350 or 360. 

My stock donk Evo 9 makes 325kw with 500nm by 4000rpm with 24psi. A well setup 7670 should blow around 420kw "all in" give or take. 

Id say 8374 if you were prepared to go V cam. But i personally think itd be a bees dick too big for a nice street setup. 

Though in saying that itd still be on around the same time if not sooner than a set of 9s or 7s ?

 

[Lithium]

15 hours ago, Mick_o said:

Not likely a 7670 would be limited to 350 or 360. 

My stock donk Evo 9 makes 325kw with 500nm by 4000rpm with 24psi. A well setup 7670 should blow around 420kw "all in" give or take. 

Id say 8374 if you were prepared to go V cam. But i personally think itd be a bees dick too big for a nice street setup. 

Though in saying that itd still be on around the same time if not sooner than a set of 9s or 7s ?

 

This part might explain the power targets: Mild 2.6L with forged pistons and rods.... on 98

[Kinkstaah]

If 98 is a restriction than that kind of power with "no worse than current" response is impossible.

That said, something 8374 sized is going to be a minimum requirement if 98 is a must have. With an 8k rev limit the 8374 is going to be my vote too. I had a 7670 on a 2.8 and it was nosing over up top at about 6800rpm.

This was OK for me as mine was a RB25 based 2.8, not a RB26 based motor.

This may or may not be perfect if you prefer revving to 7500 instead of 8500 depending on the kind of RB26 owner you are ?

To be on the safe side of everything I would be thinking something 8374 sized is likely the best compromise of running things with safe overheads.

[burn4005]

8374 because eventually you'll want e85 and 480kw+

 

I had 400kw, got over it and now I have 500kw. I like 500 better.

Edited January 9, 2019 by burn4005

[WantGTR]

Gtx42. Don't be a bitch.

[GRKGTR]

G42-1200

[Mick_o]

6 hours ago, Lithium said:

This part might explain the power targets: Mild 2.6L with forged pistons and rods.... on 98

Ahhh Fuark what a dope...  Missed that bit! ?

Well then if 98 definately 8374 1.05 ?

[shodan]

23 hours ago, Mick_o said:

Not likely a 7670 would be limited to 350 or 360. 

My stock donk Evo 9 makes 325kw with 500nm by 4000rpm with 24psi. A well setup 7670 should blow around 420kw "all in" give or take. 

Id say 8374 if you were prepared to go V cam. But i personally think itd be a bees dick too big for a nice street setup. 

Though in saying that itd still be on around the same time if not sooner than a set of 9s or 7s ?

 

Yeah sorry, didn't really make it clear I'm not running E85- fuel system upgrade is another phase for the future.

My N1s would be similar to 7s I guess, so I could live with similar performance. From the EFR threads I read several positive comments re pre-spool transient response

Edited January 9, 2019 by shodan

[shodan]

7 hours ago, Lithium said:

This part might explain the power targets: Mild 2.6L with forged pistons and rods.... on 98

Thanks for pointing that out Lithium. I averaged that figure from anecdotal comments, from the EFR threads here and elsewhere. Can I ask about your experience or knowledge of cars with either 7670s or 8374s on stock capacity RBs? , you seem to be fairly involved with car dev in NZ

[shodan]

2 hours ago, GRKGTR said:

G42-1200

Where do these fit in the Garrett pecking order? Better than GTX? different?

Edited January 9, 2019 by shodan

[shodan]

On 1/8/2019 at 2:05 PM, HarrisRacing said:

Go with the 8374. You will NOT be disappointed

I'm not at all surprised at your response 

7 hours ago, Kinkstaah said:

If 98 is a restriction than that kind of power with "no worse than current" response is impossible.

That said, something 8374 sized is going to be a minimum requirement if 98 is a must have. With an 8k rev limit the 8374 is going to be my vote too. I had a 7670 on a 2.8 and it was nosing over up top at about 6800rpm.

This was OK for me as mine was a RB25 based 2.8, not a RB26 based motor.

This may or may not be perfect if you prefer revving to 7500 instead of 8500 depending on the kind of RB26 owner you are ?

To be on the safe side of everything I would be thinking something 8374 sized is likely the best compromise of running things with safe overheads.

Yeah 98 for now. E85 sometime in the future.. Good advice thanks mate. I did read your EFR thread comments about the 7670

3 hours ago, burn4005 said:

8374 because eventually you'll want e85 and 480kw+

 

I had 400kw, got over it and now I have 500kw. I like 500 better.

Haha I'm sure that's exactly how it goes. I have been considering it for sure. Just wondering if I'm better off with the 7670 for a boost in response now, (and live with reduced total power) then moving to an 8374 when i eventually go 2.8.

[GRKGTR]

6 hours ago, shodan said:

Where do these fit in the Garrett pecking order? Better than GTX? different?

Brand new release for 2019 and improved over GTX range i believe.

Although have not seen any real world data just yet.

[Taha]

6466   if your  going to build a stroker later  6266 if your staying 2.6 or a gtx382 or 84

[HarrisRacing]

Yeah sorry, didn't really make it clear I'm not running E85- fuel system upgrade is another phase for the future.
My N1s would be similar to 7s I guess, so I could live with similar performance. From the EFR threads I read several positive comments re pre-spool transient response

I'm telling you...the 8374 will CRUSH your N1s on boost threshold, response, overall power, midrange torque etc...yes on even a stock 2.6

I have a car with new -7, fresh motor, camgears, haltech. Then I just installed a .92 8374 efr on a stock 2.6 car. No kidding the efr absolutely destroyed them both as a better operating engine. I think it's pointless to go with anything smaller to be honest because you really don't spool any faster...only reduce topend.

[shodan]

19 hours ago, Taha said:

6466   if your  going to build a stroker later  6266 if your staying 2.6 or a gtx382 or 84

Re the Precisions- .84 or 1.05 a/r ?

Edited January 11, 2019 by shodan

[33GTRV]

6466 with a .84 got me 500kw and full boost at 3750-3850 (40psi) albiet with a modified head. 

[r32-25t]

Is that on a 2.6?

[sneakey pete]

On 1/9/2019 at 7:47 AM, Kinkstaah said:

This may or may not be perfect if you prefer revving to 7500 instead of 85009500 depending on the kind of RB26 owner you are ?
 

Fixed that for you

Mate of mine is doing a 26 7670 build should be running in the next few months, will be interesting seeing how it goes compared to my 8374. Can't say i'm 100% convinced its the better option for pure street duties, though wouldn't go a 7670 for the track etc.